Disk harrow



' 23, 1944- R. T. EVANS ETAL 2,349,257

DISK HARROW Original Filed Feb. 16, 1942 2 Sheets-Sheet l HA R A5, /f/Echf F0575@ HARM;

OM l'Y W' A Tro/@fe YJ ay 239 194% R.. T. EVANS 'r AL DISK HARROW Original Filed Feb. 16, 1942 2 Sheets-Sheet 2 For? THE FIRM A 7" TOQVEVJ Patented May 23, 1944 msx HAaaow Russell T. Evans and John H. Clasen,

Anaheim, Calif.

Continuation of application Serial No. 431,010,

20, 1943, Serial No. 473,030

February 16, 1942. This application January 2.0 Claims.

(Cl. v55-73) inclined at an angle to -the line of 4travel of the implement and a rear gang of disks is mounted behind the front gang of disks with its axis oppositely inclined to the line of travel. In operation the two gangs create two couplesv which v combine additively to set up a strong tendency for the harrow to swing to one side about a vertical axis located substantially centrally of the harrow. 'I'his tendency is resisted by a lhitch mechanism connecting the front end of the harrow to a tractor or other pulling agency.

A disk harrow of the particular type to which the present invention is directed is provided with land wheels that are vertically adjustable relative to the disks. During cultivating operation the distribution' of the weight of the harrow between the land wheels and the disks depends upon the adjustment of the wheels vertically with respect to the disks, and the consequent depth of soil penetration by the disks likewise depends upon such vertical adjustment. It is one object of the present invention to provide efficient means for vertically adjusting theland wheels with respect to the disks, thereby 'to contrciil the depth to which the disks cut into the sol.

It' is one object of the invention to achieve certain advantages in the operation and con# trol of a disk harrow by arranging for one ofv the wheels to ride on relatively hard and rela- 'tively undisturbed soil and to do so without positioning such wheel laterally. away from the harrow path. In this regard a feature of the invention is the concept of causing such a wheel to track in 'a furrow formed by a forward disk. the bottom of the furrow being relatively compact earth. The other wheel, -of course, rides on the loose soil displaced by the iront gang of disks and sinks into the soil to 'a much greater extent than the furrow-'tracking wheel,v the diierential in soil penetration by the two wheelsL depending both l upon .the character of the soil and the depth to which the soil is loosened by the disk.

One of the major objects oi o'ur invention is to provide for automatic differentialy positioning of the two wheels-vertically in accord with the depth of penetration of the disks, so that when the disks penetrate relatively deeply into the soil, compensation is made for the resultant relatively deep sinking of the wheel that rides on the loosened dirt. Since vertical adjust,- ment of the two wheels is relatively to the harrow frame, the adjustment action may, com versely, be regarded as movement of the frame relativeio the two wheels. Thus, when the differential positioning consists of lowering a wheel to compensate for increased' penetration of the loosened soil by that wheel, it may be said that the frame is tilted to achieve the compensation, even though the final position of the frame may be substantially horizontal. This object of our invention, then, may be expressed 'as tilting the frame automatically with .referL ence to the two ground wheels in accord with variations in the depth oi penetration.

The depth of penetration by the `harrow in a soil of a given character varies with the vertical spacing between the harrow frame and the two wheels. Thev varying of this vertical spacing may be regarded as accomplished by raising and lowering the wheels relative to the frame, or may be regarded as accomplished by raising and lowf ering the frame relative to the wheels. Decreasing the vertical'spacing results in lowering the disks for deeper penetration into the soil. With reference to the foregoing automatic compensating adjustment, a feature and object of our invention is to provide dierential movement of the two wheels'relative to the frame whereby in raising and lowering the two Wheels relative to the frame one of the wheels is shifted faster than the other to provide the required differential at each stage of vertical change.

In the foregoing we point out two different adjustments that are made dependent on each other, namely, adjustment ol' the vertical spacing between the frame and the two wheels and differential adjustment between the wheels themselves. A further object of our invention is to provide an independent means of adjustment for varying the wheels vertically relative to each other, or, viewed conversely, for tilting the harrow frame relativeV to the wheels. A feature of our invention is that the provision oi this independent means `accomplishes two iurtherobjects of the invention. One of these further objects is to provide adjustment means to compensate for variations in character of soil since a wheel with agiven load will penetrate much deeper in loosened soil of one character than in loosened soil o! another character. The

adjustment means for tilting the harrow laterally to cause the disks to shift earth to one side or the other, thereby building up the soil level on one side of the path of the tractor and cutting down the soil level on the other side. Thus the present apparatus may be employed to correct undesirableground contours caused by repeatedly traversing the ground over a period of years with conventional disk harrows.

All such adjustments of the two land wheels.

relative to each other tending to tilt the harrow frame laterally result in varying the proportions of the frame weight imposed on the two wheels. From one viewpoint it may be said that the adjustments of the two wheels vertically relative to each other are carried out for the purpose of varying .the distribution of weight imposed on the wheels and thereby varying the degree to which the wheels penetrate the soil.

A stili further object in the preferred practice of. our invention is to provide a system for controlling the vertical spacing between the barrow frame and the two wheels whereby a manual means may be employed to determine a normal spacing and independent means, preferably in the form of power-driven means, may be employed to increase the spacing thereby to lift the disks for such purposes as making turns and temporarily reducing resistance to forward travel.

Other objects and advantages of the invention will be apparent from the following description, taken with the accompanying drawings.

In the drawings, whichrare illustrative only,

Fig. l is a plan view of a disk harrow embodying the invention;

Fig. 2 is a side elevation of the harrow;

Fig. 3 is a side elevation, partly in section, of 'the depth-regulating mechanism found in Fig. 2:

Fig. 4 is a perspective view of a modified form of the invention, the view, however, illustrating the depth-regulating frame found in Figs. 1 and 2;

Fig. 5 is a side elevation o'f a hitch mechanism connecting the forward end of the harrow to the rear end of a tractor:

F18'. 6 is a vertical section taken along the line B-of Fig.5; and

Fig. '7 is an enlarged detail view, in side elevation, showing the forward end of the harrow and the rear end of the hi.:h mechanism.

In the following description, the words land and land side" are used to refer to that side of theharrow which is directed toward ground untraveied on previous runs of the harrow in the operation of a single harrowing of the field. 'Ihe words furrow" or furrow side are used to refer to the side of the harrow opposite the land side.

The barrow includes a main frame I I, a forward gang frame 43 carrying forward disks 26, a rear gang frame 4I carrying rear disks 3|, a hitch frame 45, a depth-regulating frame 58, a depthadjusting mechanism generally designated |50, and a power-actuated mechanism generally designated ISI for elevating the front end of the harrow. The harrow is shown hitched to a-tractor, the transmission and axle housing Ii! of which and the rear wheels IIB of which are shown in phantom lines in Fig. 5.

The main frame, as best illustrated in Figs. l and 4. comprises a central, longitudinally disposed angle-iron bar I2, a somewhat shorter, land side angle-iron bardt. and a somewhat longer, furrow side angle-iron bar Il, these three angleiron bars I2, I3,fand Il being rigidly held in parallel spaced relationship by forward and rear angleiron laars- I5 and I8 of the front sang frame u,

4other of these two further objects is to provide and forward and rear angle-iron bars II and Il -of the rear gange frame Il. The angle-iron bars i5, IB, I1, and Il are each welded to all three of the longitudinally positioned bars I2, I3, and Il. the angle-iron bars I5 and I8 being inclined rearwardly toward the land side of the harrow in parallel spaced relationship to form a part of the front gang frame 43, and the rear gang bars I1 and I8 being inclined forwardly toward the land side of the harrow with respect to the longitudinal bars I2, I 3, and Il in parallel spaced relationship to form a part of the rear gang frame M.

. The front gang frame 43 is completed by end members I8 and 20, bearing-supporting bars 23 and 23a, and two bars 24 which connect the lower ends of the bars 23 and 23a respectively to the angle-iron bar I6. These several frame elements are welded together in the relationship shown In the drawings. The end member I9 is preferably formed to present in plan view a howed contour conforming to the convex side of that one of a gang of disks 28 nearest the land end of the harrow. The furrow end member 2l is formed to conform to the vertical plane of the cutting edge of that one of the gang of disks 26 nearest the furrow end of the harrow.

The cutting disks 2B are mounted on a sans rod assembly 21 rotatably mounted in two bearing boxes 25, the latter being secured to the under side of the bearing-supporting bars 2l and 23a respectively. The front gang frame is so podtioned with reference to the mainframe bars I2,

I3, andA Il that it projects substantially further beyond the main frame bar Il toward the land side of the barrow than it projects beyond the main frame bar Il toward the furrow side of the harrow, two of the disk blades 26 being placed outside of the bar Il and only one disk blade 2l belngplaced outside of the bar Il. 1

The rear gang frame Il is constructed in a fashion similar to the front gang frame 43, com- Dri-Sing a straight, land end member 2|, a bowed furrow end member 22, bearing-supporting bars 28, and bars 29 connecting the bars 2l at their lower ends to the rear gang forward bar `I1. A gang of disk blades II are rigidly mounted on a gang rod assembly 32 which is rotatably moimted.

in bearing boxes 30 secured to the under sides of the bearing-'supporting bars 28 respectively. The rear gang frame Il is so related to the main frame bars I2, I3, and Il that two of the rear gang disk blades 3| are positioned outside of the bar Il projecting toward the furrow side of the harrow, and only one disk blade 3l is outside of the main frame bar I3 projecting toward the land side of the harrow. This relative positioning of the front and rear gangs of disks provides for proper throw of the earth first toward the furrow side of the harrow, and then toward the land side of the harrow, and places the draft line of the harrow as a whole substantially in the vertical plane of the main frame bar I2.

The hitch frame 45 is constructed and related .to the rigidly associated main and gang frames bar Si. The cross-bar Il consists of a length 35a of angle-iron reinforced by an angle-iron Il disposed to form with the angle-iron a a bar bar 42, welded. to the cross-bar'35 and hitch bar 4|, strengthens. the hitch frame 45.

For hinged connection to the front gang frame 43, the hitch-frame 45 is provided with brackets 35 and 31 at one end and brackets 38a and 31a at the other en'd. A hinge bolt 38 carried by the bracketsl 36 and 31 passes through a bracket plate 33 depending i'rom a short angle-iron 84. In like manner a hinge bolt 38a carried by bracketsj35a and 31a passes through a'bracket plate 33a depending from an angle-iron 34a.

To vary the rproportion of the weight of the harrow that is imposed upon the disk blades by the use of land wheels we provide a wheelsupported. depth-regulating frame 50. depth-regulating frame 58 includes a cross-rod or shaft 5| upon the land end of which is rotatably mounted a ground wheel 52. Such a ground wheel may be pneumatic-tired as indicated in the drawings, or may be a conventional ironrim wheel commonly employed on agricultural implements. l

To the furrow end of the cross-rod 5I is rigidly secured a radius bar 53 and a shorter parallel bar 84. 'The radius bar 53 and the parallel bar 54 straddle a furrow-side ground wheel 52a and are interconnected by a short axle 55 on which the Wheel 52a is mounted. The radius bar 53 extends rearwardly to a pivotal connection with the harrow frame, the pivotal connection being provided by a pivot bolt 11 in a pair of converging, hanger bars 56 and 51, as best shown in Fig. 4. y

The land end of the cross-rod or shaft 5I is connected to the land end of the hitch frame to by means of a radius bar 5B, the radius bar being pivotally connected at its rear end to the shaft 5| and being pivotally connected at its front end by a hinge pin 6| to a rearward flange 58 of the cross-bar 35 and a bracket 88 welded to the rear face of the cross-bar. Y

The wheeled depth-regulating frame 58 is.

likewise linked with the harrow frame at each end by a suitable weight-supporting linkage associated witha cross-shaft 62. As indicated in Fig. 4 the cross-shaft 62 may be J'ournaled in three bearings 88 mounted on the under side of the three main frame angle-bars i2, i3, and i4 respectively. The linkage 4connection at the land side of theharrow may comprise a pair of link bars 13 pivotally connected to the shaft 5| and an arm 1i pivotally connected to the link.

bars 13, the arm 1l being rigidly mounted on the cross-shaft 82. In the particular arrangement shown in Figs. l and 4. the arm 1| extends between the upper ends of the link bars 13 and is connected to the link` bars 13 by a bolt or hinge pin 15. I oprovide adjustability in the position of the link bars 'I3 for a given angular position of the arm 1| two or more spaced holes 14 maybe provided in each of lthe link bars 13. in which holes the bolt or hinge pin -15 may be inserted selectively.-

For the purpose of providing a link connection at' the furrow side oi' the harrow, the depthregulating frame 58 may includea bracket member 88 for pivotal connection to the lower end of an upwardly extending pair of link bars 58.

As shown in Fig. 4, the two link bars 65 are pivotally connected to an arm 64 that is rigidly mounted on the cross-shaft 82. For adjustment in the positioning of theA two link bars 66 for a given angular position of the arm 64 the two link bars may have spaced holes 51 to receive This 4 selectively a bolt or hinge pin 8l for pivotal' connection to the arm 54.

For most operating conditions, the eiective lengths of the link bars 55 as determined by the selected position of the hinge pin 58 will be substantially equal to the lengths of the link bars 13 as determined by the selected position oi' the hinge pin 15. It is to be noted, however, that the length oi the arm 54 on the cross-shaft 62 is substantially greater than the length of the other arm 1| on the cross-shaft. Because oi' the difference in lengths of the two arm's 64 andv'li, the link bars 88 on the furrow side move at faster rates than the link bars 13 on lthe land side when the cross-shaft 82 is rotated. Consequently, the two land wheels 52 and 52a. are moved differentially with respect to the harrow frame whenever the cross-shaft 62 is operated.

Fixedly -mounted on the cross-shaft 62 is a control arm 18 which is continuously urged clockwise (as viewed in Figs. 2. 3, and 4) by the weight of the harrow acting through the arms 84 and 1l on the cross-shaft. In the preferred.

form of our invention illustrated in Figs. l to 3. such clockwise rotation of the arm 18 is limited by a stop arm 18a, the stop arm 18a being placed in the clockwise path of the control arm. The stop arm 18a is mounted on one arm of a threearm actuating lever by means of a pivot bolt 8i. VThe three-arm actuating lever 98 passes around the cross-shaft 62 from below and is pivotally connected to the control arm 18 by a suitable pivot bolt 98a. The normal position oi' the stop arm 18a and therefore the normal position of the control arm 18 are controlled by what may be termed a reach rod 19.

The reach rod '19v has an internally threaded bore 88 to receive a. screw-threaded rod 84. The rear end of the rod 84 is keyed by a pin 88 to a crank 85 having a handle 81. The hub of the crank arm 85 abuts against the rear end of a tubular sheath 8|, the reach rod 19 extending rotatably through the sheath. The sheath 8| is welded to an anchoring trunnion 82'that is journaled in the upright angeg, of a short channel section 83, the channel section being welded to the rear, end of the main frame bar I2. When the arm 85 is turned in a clockwise direction, the rod 19 is pulled rearwardly to rock the control arm 18 and the cross-shaft 82 counter-clockwise. Such counter-clockwise rotation of the shaft 82 acting through the arms 84 and 1i increases the vertical spacing between the level of the harrow frame and the level of the ground wheels 52 and 52a; thereby raising the harrow frame', Reverse movement of the crank arm 85 causes the contrary action to lower the harrow frame together with the harrow disks. A stop collar 88 on the reach rod 19 moves against the forward end oi' the sheath 8| to lix an upper limit to the elevation of the harrow frame while the cross-shaft '5| arm lever and a chain 83 connected to the clevis..

The chain 83 extends forward to a lever 94 that i`spivotally mounted on the tractor transmission and axle housing H5. The lever 84 is controlled Y by a ccnnecting'rod 95 e.` hydraulic cylinder from a piston 98 within 81, the hydraulic cylinder connected to the the soil is to be penetrated. Hy

4 being connected in a well known manner to a hydraulic pipe system generally designated Il.

Actuation o! the piston l in the cylinder 01 is controlled by a suitable manually operable valve 00. Movement of the piston 00 in a forward direction acting through the lever M and the chain pulls the lower end of the three-arm lever ll forward to cause the three-arm lever to fulcrum on the' cross-shaft 02. Since the upper end of the three-arm lever 90 is pivotally end of the control arm 18, the movement of the three-arm lever about the crossshaft 02 as a fulcrum swings the control arm 18 backward or counter-clockwise to elevate the harrow frame with respect to the ground wheels l2 and 02a. It is apparent that opposite movement of the piston l0, l. e., rearward movement. causes the harrow trame until the control arm 18 swings against the stop arm 18a.

It is apparent that the adjustment of the reach rod 1S by operation of the crank arm 00 determines what may be termed a normal lower limit ot the range of 'adjustment of the harrow frame with respect to the ground wheel. This normal limit may, of course, be changed as desired simply by rotating the crank arm 0I. In one practice of the invention the crank arm is rotated to a position normal for the particular soil to be worked and normal for the desired depth to which ullc operation of the three-arm lever 90 is thereafter employed temporarily as required, for example, to make a right-hand turn or to pass over an obstacle. If desirable, the crank elevate the harrow frame above the particular level represented by the instant position of the piston 90. On the other hand, rotation of the cranky in the opposite direction will not result in lowering the barrow frame below the level represented 'by the instant position of vthe piston 0i. In vother words, the harrow frame will seek whichever level is lowest, the level represented by the instant adjustment of thecrank 00 or the level represented bythe instant position of the piston l0.

Figs. 5, 6, and 'l indicate how a power-lift mechanism generally designated ISI may be employed in commotion with the hitch frame l5 for the purpose of exerting lifting force on the front end of the harrow. As best shown in Fig. 6, an

A iframe |00 comprises a pair of upright converg ing side bars |02, an upper cross-rod |03, and a lower cross-rod |04. the cross-rods being rigidly secured to the side bars |02. The A frame |00 also includes as a rigid portion thereof a transverse tube |2| by means of which the A frame is rotatably mounted on a cross-rod |20, the cross-rod |20 being carried by a pair of spaced angle-irons |0| extending-rearwardly from the transmission and axle housing H5 of the tractor. Each of the bars |0| may be reinforced by triangular vertical plates ils which are interconnected by a transverse angle-iron ill. The particulai` construction shown in Figs. 5 and 6 is mounted on a tractor having power-actuated lift arms i0, the .A frame and the mounting for the A frame lying between` the two lift arms.

Rotatably mounted on the lower cross rod |00 of the A frame |00 is a tube |00 integral with a rearwardly extending hitch plate |01, the plate having a plurality of transversely spaced hitch apertures lli. At the forward end of the hitch bar 4| is mounted a swivel block |00 in which is arm as may be rotated to` to be lowered by gravity :lournaled a swivel secured against forward displacement relative to the swivel block -by a retaining pin ill and against rearward displacement by an integrally formed head I. A pair of clevis bars ||2 welded at their rear ends to the head is pivotally connected to the hitch plate |01 by a hitch pin H3 which may be positioned selectivelyy in any of the hitch apertures lil. l

A chain |21 is connected tothe'uppeir end of .v the A frame |00 by means oi'a connectinglnenl.- ber |00 that rotatably-embraces the uppery cross-- rod |03 of the A frame. The nected to the upward forward end chain |21 is conchain |23 is connected at one of its ends to an anchor clip |24 positioned as shown in Fig. l on the front bar I5V of the 43 and is connected at its other end to the hitch bar 35 of the hitch frame I5 by means o f a wrap about the angle-bars 35a and 40. The upper end of the A frame |00 is likewise connected by a chain |26 to the upper end of an actuating lever |28 on the rear of the tractor, the chain |26 being attached to the previously mentioned con. necting member |05 that is journaled on the upper ycross-rod |03 of the A frame. The1 lower arm of the lever |28 is connected by a connecting rod |30 to a piston |3| in a. hydraulic cylinder |32.

of the piston |3| in the hydraulic cylinder is con'- trolled by a manually operable valve |33.

Rearward movement of the piston |3| swings the lever |28 clockwise and by virtue of the chain |20 likewise causes the A frame |00 to swing clockwise on its axis. The thrust thus administered to the bar 4| together with the simultaneous pull given to the rod |22 will lighten the weight of the harrow carried bythe forward disks 26. Sufllcient rearward movement of the l piston ill may lift the front disks to cause the harrow to tilt rearward on the land wheels 52 and 52a. Excessive rearward movement of the piston vmay even be employed, if desired, to lift both the front gang 'of disks and the two wheels 02 and 52a from the soil. It will be readily apparent to those skilled in the art that the hook |25 at the lower rearward end of the rod |22 may be shifted to various links of the chain |28 Vto vary the harrow-lifting eileet for given positions of the piston |3| and the A frame |00.

It is to be noted that the manner in which the harrow works the soil may be varied both by varying the spatial relationship of the two wheels 52 and 52a with respect to the harrow frame and by varying the lift force excl-'ted upon the forward end of the harrow frame through the described hitch arrangement, the preferred form of the hitch arrangement being the powerlift mechanism generally designated |5I. The manner in which these two modes of adjustment are employed for various types of soil and various working conditions will lie within the judgment of the operator. While 'the arrangement is quite flexible'in affording a wide choice of adjustments, it is no t diiiicult to. master and only the usual skill and knowledge of implements are v required on the part of the operator.

Since the harrow is usually given suillcient weight to meet the most severe, ground conditions, the two ground wheels 02 and 52a are adpin 00. The swivel pin |00 is` of a rod |22, which rod is formed to a hook-|25 at its rear-g. y ward lower end for engagement with a chainV |23. The hook |25 may be selectively engaged j with the various links of the chain |23. The

forward gang frame lusted to carry a portion of the weight of the harrow whenever maximum application` 4of the weight of the harrow is not required. Thus, for a given penetration of the soil, the vertical spacing between the'level of the harrowframe and the level ofthe ground wheels 52 and 52a will be such that the ground wheels take that share of the weight of the harrow that is not required for the desired depth of penetration. Usually the adjustment of the two land wheels is such `that the harrow frame is substantially level and all of the various disk blades penetrate the soil to substantially the same depth. If. however, it is desired that the .soil be shifted in one direction or another, the hinge pins 68 and 15 may be shifted as required to cause the harrow frame to tilt laterally toward one side or the other.

The ground wheel 52 travels'in the furrow made by the'disks 26 directly in front of the ground wheel, the furrow being subsequently covered by.

dirt displaced by the rear gang behind the land wheel. Preferably, the ground wheel 52 is so positioned and arranged that it rides alongside and crowds somewhat against the land wall of this furrow, thereby steadying the harrow against lateral deviations fromits line of travel and giving it a relatively firm foundation level with reference to which the depth of cut of. the two gangs of disks is determined. A minor quantity of soil drops into the furrow, especially ii` the wheel 52 crowds against the land wall of the furrow.. Preferably, the width of the tread of the wheel 52 is somewhat greater than the width of the furrow so that the'wheel rides somewhat on the sides of the furrow to'displace a minor quantity of earth into the bottom of the furrow. Nevertheless the quantity of' earth interposed between the wheel and the bottom of the furrow is not large and the interposed earth is compressed by the wheel into compactness comparable with, if not greater than, the compactness of the undisturbed earth forming the natural bottom of the furrow. It is apparent, then, that the land-side wheel 52 rides over compact earth at the bottom of the furrow and does not sink into or penetrate that compact earth to.

any relatively great extent for a given wheel load.

Since the wheel 52 rides upon relatively com-7 pact earth regardless of the depth of penetration of the harrow disks and sinc'e `the compactness of the earth under the wheel minimizes variations in penetration ofthe wheel in response to variations of loading placed on the wheel, it will be readily understood that the level of.the bottom of the wheel 52 relative to the level of the freshly scooped bottom of the furrow in which it rides will notvary greatly at various adjustments of weight distribution between the two wheels on the one hand, and the gangs of disks on the other hand. In contrast, the wheel 52a on the other side of the harrowrides on soft and loosened soil displaced by the front'gang of disks, and it will be found that the wheel 52a will penetrate this loosened soil to various depths under various conditions. rThe principal factors determining the depth to which the wheel 52a sinks into the loosened soil are the character oi' the soil, the instant condition of the soil with respect to moisture, the weight imposed on the wheel, and the thickness or depth of the layer of loosened soil.

Under a given loading the wheel 52a may sink one inch intoa layer of loosened soil two inches thick and with the same loading may sink two or two and one-half inches into a four-inch layer of loosened soil. In the first instance, the wheel 52a will travel on a level approximately one inch higher than the level of the wheel 52 in the furrow on the land side, while in the second instance the level of the wheel 52a will be approximately one and one-halt or two inches above the level of the land-side wheel 52. An important feature of the invention is our concept of providing for the described differential movement of the two wheels 52 and 52a in response to angular movement of the control lever 18, the purpose of providing such diierential movement being to compensate for the differences in level of the two wheels 52 and 52a at the different depths of soil penetra tion as. determined by the diilerent elevations of the harrow frame with respect to the two wheels.

The required differential movement is achieved by making the arm 54 suitably longer than the arm 1| as heretofore noted. It is contemplated that the compensation will be suchthat the position of the harrow frame with reference to lat-y eral tilt will be substantially constant at various depths of penetration of a given soi1 by the har- -row disks.

Whether the substantially constant position of the harrow frame will be substantially horizontal or will be tilted to one side 'or the other for a given soil will depend-upon the adjustment of the two arms 64 and 1| with respect to the holes in which the hinge pins 88 and 15 are placed.

" It is to be noted that the adjustment provided by I' the series oi' holes 14 tion. Thus.

Y one of said wheels ,the frame of the series of holes 51 for the hinge pin 58 and for the hange pin 15 is independent of and in addition to vertical adjustment of the depth-regulating frame 50. and

that this additional adjustment may be employed either to cause the harrow to maintain a laterally tilted positionV or maybe employed to compensate for variations in the character and condition of the soil to the end that the harrow may normally ride in a substantially horizontal posi if the soil is somewhat lighter than usual so that the wheel 52a tends to-drop closer than usual to the level of the wheel 52, the hinge pin 15 maybe shiftedto an upper hole 1I,v the hinge pin 68 being in a lower hole 81.

The specific description and illustration herein of a preferred form ot our invention will suggest to those skilled in the art various changes and substitutions under our inventive concept, and we reserve the right to all such departures that lie within the scopeof our appended claims.

We claim as our invention:

1. A harrow having in combination: a frame;

a plurality of soil-working members carried by vsaid frame; a pair of laterally spaced ground wheels to support said frame to various degrees, being positioned to ride upon relatively 'compact soil and the other of said wheels being positioned to rideupon a layer of relatively loose soil displaced by said soil-working members:

saidwheel that rides on compact soil; and means to shift, simultaneously in the same direction but at a greater rate the level relative to the frame of said wheel that rides on relatively loose soil, frame relative to the two wheels may be varied to vary the depth of penetration of said members and whereby in varying the relative level ofthe frame compensation is made for variations in the differences inlevel ot said wheels at different I depths of soil penetration by'said members.

meansto shift the level relative to whereby the elevation of the disks being `concave in said frame; a pair of laterally spaced ground wheels to support said frame to variousdegrees; means to shift said wheels simultaneously relative to said frame at different rates to vary the level of said frame relative to said two wheels, thereby to vary the proportion of the frame weight carried by the wheels and the extent to which saidmembers penetrate the soil; and means independent of said shifting means to tilt the frame laterally relative to said two wheels, whereby the frame may be positioned relative to the wheels to compensate for relatively deep penetration of the soil by one wheel to cause all of said members to penetrate the soil to substantially the same depth or may be positioned relative to the wheels to cause greater soil penetration by said members on one side of the harrow than on the other side of the harrow.

3. A harrow having in combination: a frame; a front gang of disks carried by the frame, said disks being concave in one lateral direction so that an end disk leaves in its wake an open furrow; a rear gang of disks carried by the frame; a pair of laterally spaced wheels between said gangs of disks to support said frame to various degrees. one of said wheels being positioned to ride on relatively compact earth in said furrow, the other wheel being. positioned to ride on the layer of relatively loose earth displaced by said front gang of disks; and means to shift said vwheels relative to said frame to vary the level of said frame relative to said two wheels, thereby to vary the proportion of the frame weight carried by the wheels and the extent to which said disks penetrate the soil, said shifting means being adapted to shift the wheel that rides on loosened soilat a faster rate than the wheel that rides in the furrow, thereby to' compensate at least in part for changes in the levels of the two wheels relative to each other at different depths of soil penetration by said members.

4. A harrow having in combination: a frame; a front gang of disks carried by the frame, said one lateral direction so that an'end disk leaves in its wake an open furrow; a rear gang of disks carried by the frame; a pair of laterally spaced wheels between said gangs of disks to support said frame to various degrees, one of said wheels being positioned to ride on relatively compact earth in said furrow,

the other wheel being positioned to ride on the layer of relatively loose earth displaced by said front gang of disks; means to shift said wheels relative to said frame to vary the level of said frame relative to said two wheels, thereby to vary the proportion of the frame weight carried by the wheels and. the extent to which said disks 'penetrate the soil, said shifting means being adapted to shift the wheel that rides on loosened soil at a faster rate than the wheel that rides in the furrow, thereby to compensate at least in part for changes in the levels of the two wheels relative to. each other at dierent depths of soil penetration by said members; and means independent or seid shifting means to tut the frame laterally relative to said two wheels, whereby the frame may be positioned relative to the wheels to compensate for relatively deep penetration of the soil by one wheel to cause all of said members to penetrate the soil to substantially the same depth or may be positioned relative to the wheels to cause greater soil penetration by said members on one side of the harrow than on the other side of the barrow.

'5. A harrow having in combination:y a frame;

Ywheels to support Said soil-working members carried by laterally spaced ground a plurality of said frame; a pair of wheels to support said one of said wheels being Psitioned to ride upon relatively compact soil and the other 4of said wheels being positioned to ride upon a layer of relatively loose soil displaced by said soil-working members; means to shift the level lrelative to the frame of said wheel that rides on compact soil; means to shift simultaneously in the same direction but at a greater rate the level relative to the frame of said wheel that rides on relatively loose soil, whereby the elevation of the frame relative to the two wheels may be varied to vary the depth of penetration of said members and whereby in varying the relative level of the frame compensation is made for variations in the dif ferences in level of said wheels at different depths of soil penetration by said members; and means independent of said shifting means to vary the vertical spacing of one of said wheels relative tothe frame.

6. A harrow having in combinatlonza frame; a plurality of soil-working members carried by said fra e; a pair of laterally spaced ground frame to various degrees, one of said wheels being positioned to ride upon relatively compact soil and the other of said wheels being positioned to ride upon a layer of relatively loose soil displaced by said soil-working members; means to shift the level relative to the frame of said wheel that rides on 'compact soil; means to shift simultaneously in the same direction but at a greater rate the level relative to the frame of said wheel that rides on relatively loose soil, whereby the elevation of the frame' .working members carriedby said frame; a pair of laterally spaced ground wheels positioned lntermediate the two pluralities of soil-working members to support said frame to various degrees, one of said wheels being positioned to' ride upon relatively compact soil andthe other of said wheels being positioned to ride upon relatively loose soil displaced by said members; means to shift said two wheels relative to the frame, thereby to vary the depth of soil penetration by said members, said shifting means being adapted to shift the wheel that rides on loose soil at a faster rate vthan the wheel that rides on compact soil, thereby to compensate for variations in the differences in level oi' said wheels at different depths of soil penetration by said members; and variablemeans to exert a llftin! force on the leading end of said frame.

8. A harrow having. in combination: a frame: a plurality of soil-working members carried by said frame; a pair of laterally spaced ground wheels to support said frame to various degrees; means to shift said wheels simultaneously relative to said frame at different rates to vary the level of said frame relative to said ytwo wheels, thereby to vary the proportion of the frame weight carriedfby the wheels and the extent to frame to various degrees.

etration of'the soil by one wheel to cause all oi' said members to penetrate the soil to substantially the same depth or may be positioned relative to the wheels to cause greater soil penetration by said members on one side of the harrow than on the other side of the harrow; and var- -iable means to exert a lifting force on the leading end of said frame.'

9. A harrow having in combination: ajframe; a front gang of disks carried by the frame, said disks being concave in one la ral direction so that an end disk leaves in its wa e an open furrow; .a rear gang of disks carried by the frame: a pair of laterally spaced wheels .between said gangs of disks to support said'frame to various degrees, one of said wheels being positioned-to ride on relatively compact earth in said furrow, the other -wheel being positioned to ride on the layer of relatively loose earth displaced by said front gang of disks; means to shift said wheels relative to said frame to vary the level of said frame relative to said two wheels, thereby to vary the proportion of the frame weight carried by the wheels and the extent to which said disks penetrate the soil, said shifting means being adapted to shift the wheel that rides on loosened soil at a faster rate than the Wheel that rides in the furrow, thereby to'compensate at least in part for changes in the levels of the two wheels relative to each other at different depths of soil penetration by 'said members; and variable means to exert a lifting force on the leadingend of said frame. o i

10. A harrow having in combination: a frame; a plurality of soil-working members carried by said frame; a pair `of laterally spaced ground wheels to support said frame, one of said wheels being positioned to ride on relatively compact ilrst rotary means having a g'ivenvertical throw ing means including a rotary member with av verticalthrow greater than said given vertical throw, whereby. the wheel that rides on soft soil is shifted at a faster rate than thewheel that rides on compactl soil, thereby to compensate for variations in tht differences in level 'of said wheels at different depths of soil penetration by .said members.

12. A harrow having in combination: a frame; a front gang of disks carried by the frame, said disks being concave in one lateral direction so that an end disk leaves in its wakean open furrow; a rear gang of disks carried by the frame; a pair of laterally spaced wheels between'said gangs of disks to support said frame to various degrees, one of said wheels being positioned to ride on relatively compact earth in said furrow, the other wheel being positioned to ride on the layer of relatively loose earth displaced by said soil and the other of said wheels being positioned A to ride on relatively loose soil displaced by said soil-working members; a first means to shift relative to the frame the'wheel that rides on compact soil, said first shifting means including a first rotary means having a given vertical throw controlling the vertical shift of the wheel; and a second means operable simultaneously with said first means to shift relative to the frame the wheel that rides on loose soil. said second shifting means including a rotary member with a vertical throw greater than said given vertical throw, whereby the wheel that rides on soft soil is shifted at a faster'rate than the wheel that rides on compact soil, thereby to compensate for variations in the differences in level of said wheels at different depths of soil penetration by said members.v

' 1l. A harrow having in combination: a frame; a front gang of disks carried by the frame, said disks being concave in one lateral direction so that a'n end disk leaves in its wake an open fur row; a rear gang of disks carried by the frame: a pair of laterally spaced wheels between said gangs of disks to support said frame to .various degrees, one of said wheels being positioned to ride on relatively compact earth in said-furrow, the other wheel being positioned to ride on the layer of"relatively loose earth displaced by said front gang of disks; a first means toshift relative to the frame the wheel that rides on compact soil, said first shifting means including a a plurality of soil-working members carried by` front gang of disks; a ilrst means to shift relative to the frame the wheel that rides on compact soil, said first shifting means including a rst rotary means having a given vertical throw controlling the vertical shift of the'wheel; a.v

second means operable simultaneously with said first means to shift relative to the'frame the wheel that rides on loose soil. said second shift-- ing means -including a rotary member withva A vertical throw greater than said given vertical throw, whereby the wheel that rides on soft soil is shifted at a faster rate than the wheel that rides on compact soil, thereby to compensate for variations in the differences in level of said wheels at diierent depths of soil penetration by said members; and means independent of said shiftin g means to adjustably tilt said frame laterally relative to said two wheels.

i3. -A harrow having in combination; a frame; 4

a plurality of soil-working members carried by said frame; a pair of laterally spaced ground wheels to support said frame to various degrees,

one of said wheels being positioned to ride on relatively compact soil andthe other ofsaid wheels being positioned to ride on relatively loose soil displaced by said soil-working members; means to shift said two wheels relative tothe frame to vary the elevation of the frame relative to the wheels, thereby to vary the depth of penetration by said members, said shifting means being adapted to move the wheel that rides on loose soil at a faster rate than the wheel that rides on compact soil to compensate foi-,variations in the difference in level of said wheels at diilerent depths of soil penetration by said members; manually adjustable meansto set said shifting means at a minimum elevation ofsaid frame relative to said 'wheels; and power means to operate said shifting means to raise said frame above said predetermined minimum level.

14. A narrow having in combination :1 a frame;

said frame; a pair of laterally spaced ground Wheels to support said frame to various degrees, one of said wheelsbeing positioned to ride on relatively compact soil and the other of said wheels being positioned to ride on relatively loose soll displaced by said soil-working members; means to shift said two wheels-relative to the frame to vary the elevation of the frame relative to the wheels, thereby to vary the depth of penetration by said members, said shifting means being adapted to move the wheel that rides on loose soil at a faster rate than the wheel that rides on compact. soil to compensate for variations in the difference in level of said wheels at dierent depths of soil penetration by said members; a manuallyadjustable stop means to limit movement of said shifting means in one direction, thereby to determine a minimum level for said frame relative to said wheels; and power means to move said shifting means away from said: stop means to elevate said frame above said minimum level.

l5. In an offset disk harrow characterized by front and rear oppositely pitched gangs of disks, the combination of: a frame structure upon which said gangs of disks are mounted; a crossshaft mounted transversely of said frame structure between said front and rear gangs of disks; a ground wheel disposed beneath the land end of said shaft on a bearing having a horizontal transverse axis; a toggle joint linkage between said shaft and said bearing adapted when said shaft is rotated to vary the elevation of said frame structure above said wheel bearing; a ground wheel disposed beneath the furrow end of said frame structure and between said gangs and mounted on la bearing having a horizontal transverse axis; a toggle joint linkage between said shaft and said bearing of said furrow ground wl ,el adapted to vary the elevation of said frame structure above the bearing of said furrow ground wheel when said shaft is rotated and at a more rapid rate than the variation in elevation effected by said first mentioned toggle joint linkage; and means for rotating said shaft.

16. The combination defined in claim 15 in which said shaft rotating means comprises a nanually operated means and in addition to said manually operated means a power means adapted to be operated from a tractor to which the harrow is hitched to rotate said shaft from .a .position established by said manually controlled means in f a direction to elevate said frame structure above said ground wheels.

17. The combination defined in claim 15 in which said shaft rotating means consists of an upwardly extending arm mounted rigidly on said shaft in a position to be urged forwardly by the weightv of the harrow; a flexible tension member extending forwardly to the tractor and arranged when under tension to pull backwardly upon said arm; means adapted to be mounted on the tractor for applying tension to said flexible tension member; anda manually movable means adapted w actas an adjustable stop to limit forward movement of said arm.

18. In a disk harrow, the combination of a harrow frame; gangs of disks carried by sai frame; a hitch frame plvotally mounted on sai harrow frame on an axis substantially in a horizontal plane of the axes of said disks and said hitch frame extending forwardly from said harrow fr ame; a frame structure adapted to be mounted on a tractor providing a pivotal mounting on a transverse horizontal axis; an upright member medially pivoted on said mounting, the forward end of said hitch frame being connected vto the lower end of said upright member by a universal joint; a flexible tie member connecting the upper end of said upright member with the front portion of said harrow frame, the place of said connection on said front portion being adinstable from a level substantially above the level of said disk axes to a level relatively adjacent thereto; and means under the control of the tractor operator for angling said upright member about its pivotal mounting.

19. In a disk harrow, the combination of: a harrow frame; gangs of disks carried by said frame; a hitch frame pivotally mounted on said harrow frame on an axis substantially in the horl-l zontal plane of the axes of said disks and said hitch frame extending forwardly-from said harrow frame; a frame structure adapted to be mounted on a tractor and providing a pivotal mounting on a transverse horizontal axis; an upright member medially pivoted on said mounting, the forward end of said hitch frame being connected to the lower end of said upright member by a universal Joint, the upper end of said upright member being substantially above the level of said harrow frame; a flexible tie member connected at its front end to the upper end of said upright member; a chain connected at its upper end to the front portion of said harrow frame at a level substantially above the level of said disk axesv and connected at its lower end to the rear end of said hitch frame. the rear end of said flexible tie member being adapted to be connected to said chain at any point between the ends thereof; and means under the control of the tractor operator for angling said upright member about its pivotal mounting.

' 20. In an agricultural implement. a main frame including' longitudinally extending bars, front and rear disk-carrying frames carried by said,

' bars and extending diagonally of the main frame therefrom, a wheel rotatably mounted between.

in converging relation to each other toward one side of the implement. an axle extending transversely of the main frame between the front and rear frames, a shaft rockably mounted in front of said axle, a drag link between the front frame and one end of said axle, arms extending rearwardly from said shaft. links connecting said arms with said axle and rotatably supportingl the axle, a wheel carried by said axle at the end thereof engaged by the drag link, .bars carried byv they other end of said axle and extending forwardly s'aid bars in front of the axle, one bar extending rearwardly from the axle and lpivoted to the rear frame, and' means for turning said shaft and swinging its arms to shift the axle vertically and vertically adjust the position of said wheels.

RUSSELL T. EVANS. JOHN H. cLAsnN. 

